What you are talking about would work. I have a few suggestions for you to think about. The Nikon Omega has the yardage rings and they are right on when you are getting close to 2000 FPS [120 gr BH] I sight in dead on at 100yds and us the rings to shoot 6 inch gongs out to 250 yds. I have never shot over 190 for game and I don't like to shoot that far the wind and the time lag between when you shoot and when the bullet hits can combine against you till the chances of a bad hit are much greater even when your aim is dead on.
The other suggestion is that some where along the way you try Blackhorn with it you don't need to clean between shots. Cleaning between shot is not only a pain but also introduces more variables: is it as clean or cleaner than the last shot is there more or less moisture in the barrel, has powder gathered any moisture since the last time you were in the field? Blackhorn is non hygroscopic.